The invention relates to a dryer for continuous textile webs.
It is known that difficulties arise in connection with drying of textile webs, if the structure of the web edges diverges from the structure of the remaining web, either because the edges are embodied to be denser and therefore have a greater goods weight, or because the edges had been subjected to a prior sizing. In these cases the edges dry more slowly than the remaining web. In order to assure the drying of the edges, too, the machines then must be run slower. This results in a reduction of the throughput of the goods.
The invention is based on a device which has been described in DE-GM 81 11 908. In this device the blower tubes are seated at the beginning of the inlet area, if required also at the end of the outlet area, of a dryer consisting of several areas. They are provided with nozzle slits, whose blowing direction is aimed toward the web edges. In the longitudinal section in which the blower tubes are arranged, the upper blower boxes for the large surface treatment of the textile webs is missing. This measure is apparently used to provide sufficient space for housing blower tubes of relatively large cross section, as well as for the appropriately feed lines by means of which the blower tubes are connected without additional blowers to the existing circulating air system. Only a reduced drying output is possible in the inlet area because of the missing blower box. Therefore the length of the dryer must be increased accordingly. In order to keep the increase within economically tolerable limits, the longitudinal sections in which the blower tubes have been installed must be kept as short as possible. Because of this, the drying output additionally provided in the edge areas is limited.
With another dryer, which is also described in the mentioned reference, additional devices are provided outside of the actual dryer, namely upstream of the inlet area and downstream of the outlet area. Each additional device comprises an infrared radiator arranged underneath the web edge, and a blower tube arranged above the web edge. A hot air generator in the form of a blower is furthermore a part of each additional device, whose aspirating side is connected with the infrared radiator via a suction line and whose pressure line is connected with the blower tube. A decrease of the drying output of the actual dryer is prevented in this way. But additional space requirements are created upstream and downstream of the dryer. If sufficient drying of the edges is to be achieved, this space requirement is considerable. But it has also been shown that the personnel is subjected to a considerable nuisance because of the smell from such devices arranged outside of the dryer. In case of an unexpected stoppage, infrared radiators can cause damage to the continuous textile web.
A dryer known from DE-PS 37 06 615 is also a part of the prior art. With this dryer, sheet metal guide panels have been disposed on the chain rails, by which the drying medium exiting the blower boxes in the edge zones is intended to be collected and positively directed onto the edges. In this case several such sheet metal guide panels can be lined up on a partial section, not specified in detail, beginning at the dryer inlet. In connection with this dryer it has been shown, that the additional drying output conducted to the edges is relatively weak, so that it is not sufficient in all cases.